Polishing or grinding element



FIG. 1 is a front view of a polishing or grinding element;

FIG. 2 is a perspective view thereof;

FIG. 3 is a side view thereof; and,

FIG. 4 is a back view thereof.

Broken lines are used to indicate structure that does not form part of the claimed design. 

CLAIM The ornamental design for a polishing or grinding element, as shown and described. 